Sentinel lymph node mapping of breast cancer: a case-control study of methylene blue tracer compared to isosulfan blue

Isosulfan blue has been traditionally used as a tracer to map the lymphatic system during identification of the sentinel lymph node. However, allergic reactions may be life threatening. We compared the efficacy of methylene blue dye as a tracer for sentinel lymph node biopsy to isosulfan blue dye. In an analysis of 164 cases, there was no clinical or statistically significant difference in the success rate of sentinel node biopsy (P = 0.22), the number of blue sentinel nodes harvested (P = 0.46), the concordance with radioactive sentinel nodes (P = 0.92), or the incidence of metastases (P = 0.87) when methylene blue tracer was compared to isosulfan blue. No adverse reaction to either blue dye was observed. In conclusion, intraparenchymal injection of methylene blue dye is a reliable tracer for the lymphatic system and nodal identification during sentinel node mapping for breast cancer. It is safe, inexpensive, and readily available.     

Sentinel node imaging and biopsy in breast cancer patients.

BACKGROUND: Several techniques have been shown to be accurate in identifying axillary sentinel lymph nodes. The accuracy of subareolar blue dye injection is compared with intraparenchymal radioisotope injection. METHODS: Forty-two consecutive patients with breast cancer were injected with both intraparenchymal technetium-99m and subareolar isosulfan blue dye. After sentinel lymph node identification, an axillary lymph node dissection was performed. RESULTS: The blue dye and the technetium-99m localized to the same axillary nodes even though the injection sites were different. The sensitivity of blue dye in identifying axillary sentinel nodes was 100%. The sensitivity of radioisotope injection in identifying sentinel nodes was 97.6%. CONCLUSIONS: Subareolar blue dye injection is an extremely accurate and cost-effective method of sentinel node identification in breast cancer patients.     

Lessons learned from 500 cases of lymphatic mapping for breast cancer

OBJECTIVE: To evaluate the factors affecting the identification and accuracy of the sentinel node in breast cancer in a single institutional experience. SUMMARY BACKGROUND DATA: Few of the many published feasibility studies of lymphatic mapping for breast cancer have adequate numbers to assess in detail the factors affecting failed and falsely negative mapping procedures. METHODS: Five hundred consecutive sentinel lymph node biopsies were performed using isosulfan blue dye and technetium-labeled sulfur colloid. A planned conventional axillary dissection was performed in 104 cases. RESULTS: Sentinel nodes were identified in 458 of 492 (92%) evaluable cases. The mean number of sentinel nodes removed was 2.1. The sentinel node was successfully identified by blue dye in 80% (393/492), by isotope in 85% (419/492), and by the combination of blue dye and isotope in 93% (458/492) of patients. Success in locating the sentinel node was unrelated to tumor size, type, location, or multicentricity; the presence of lymphovascular invasion; histologic or nuclear grade; or a previous surgical biopsy. The false-negative rate of 10.6% (5/47) was calculated using only those 104 cases where a conventional axillary dissection was planned before surgery. CONCLUSIONS: Sentinel node biopsy in patients with early breast cancer is a safe and effective alternative to routine axillary dissection for patients with negative nodes. Because of a small but definite rate of false-negative results, this procedure is most valuable in patients with a low risk of axillary nodal metastases. Both blue dye and radioisotope should be used to maximize the yield and accuracy of successful localizations.     

Improved Lymphatic Mapping Technique for Breast Cancer

Abstract: Breast sentinel lymph node biopsy is becoming more common. However, the best injection technique is not well established. Currently the gold standard is peritumoral injection. However, for upper outer quadrant tumors there is considerable axillary “shine through” which makes the identification of the radioactive sentinel lymph node difficult. We undertook a study to compare an injection in Sappey's subareolar plexus to the gold standard of peritumoral injection. Between December 1997 and March 1998, 85 patients with breast cancer were enrolled in the study. All patients were injected with 2 cc of normal saline containing 1.0 mCi of unfiltered technetium sulfur colloid in Sappey's subareolar plexus in the clock position of the breast cancer. In the operating room the patients underwent a peritumoral injection of 5 cc of 1% isosulfan blue. All blue and radioactive lymph nodes were identified and removed. The majority of the tumors were in the upper outer quadrant and were diagnosed by core biopsy. Only half of the patients had palpable tumors and approximately 25% had previous upper outer quadrant biopsy incisions. Peritumoral blue dye injection yielded an identification rate of 94%, with 99% of these being blue and radioactive. Three patients had radioactive lymph nodes with no blue lymph nodes identified. One of these patients had a micrometastasis. Injection in Sappey's subareolar plexus in the clock position of the tumor drained to the same sentinel lymph node as peritumoral injection. This injection technique solved the two major problems confronting the wide adoption of sentinel lymph node biopsy for breast cancer staging. First, it eliminates axillary “shine through” which will allow nonspecialist surgeons to more easily identify the radioactive axillary sentinel lymph node. Second, it allows for easier isotope injection by the technician or nuclear medicine physician, by eliminating the need for three-dimensional localization. This new technique should allow the majority of breast cancer patients who are treated by nonspecialist surgeons to be offered this less morbid, more accurate procedure.     

Functional lymphatic anatomy for sentinel node biopsy in breast cancer: echoes from the past and the periareolar blue method

OBJECTIVE: To simplify and improve the technique of axillary sentinel node biopsy, based on a concept of functional lymphatic anatomy of the breast. SUMMARY BACKGROUND DATA: Because of their common origin, the mammary gland and its skin envelope share the same lymph drainage pathways. The breast is essentially a single unit and has a specialized lymphatic system with preferential drainage, through select channels, to designated (sentinel) lymph nodes in the lower axilla. METHODS: These hypotheses were studied by comparing axillary lymph node targeting after intraparenchymal peritumoral radiocolloid (detected by a gamma probe) with the visible staining after an intradermal blue dye injection, either over the primary tumor site (90 procedures) or in the periareolar area (130 procedures). The radioactive content, blue coloring, and histopathology of the individual lymph nodes harvested during each procedure were analyzed. RESULTS: Radiolabeled axillary nodes were identified in 210 procedures, and these were colored blue in 200 cases (94%). The targeting concordance between peritumoral radiocolloid and intradermal blue dye was unrelated to the breast tumor location or the site of dye injection. Radioactive sentinel nodes were not stained blue in 10 procedures (5%), but this mismatching could be explained by technical problems in all cases. In two cases (1%), the (pathologic) sentinel node was blue but had no detectable radiocolloid uptake. CONCLUSIONS: The lessons learned from this study provide a functional concept of the breast lymphatic system and its role in metastasis. Anatomical and clinical investigations from the past strongly support these views, as do recent sentinel node studies. Periareolar blue dye injection appears ideally suited to identify the principal (axillary) metastasis route in early breast cancer. Awareness of the targeting mechanism and inherent technical restrictions remain crucial to the ultimate success of sentinel node biopsy and may prevent disaster.     

Blue Dye Injection in the Arm in Order to Conserve the Lymphatic Drainage of the Arm in Breast Cancer Patients Requiring an Axillary Dissection

Background Despite the widespread use of the sentinel lymph node biopsy technique, many patients with invasive breast cancer still undergo an axillary lymph node dissection and are at risk of arm lymphedema. With the new awareness of lymphatic spread in the axillary nodes, it should be possible to define a new surgical approach between sentinel lymph node biopsy and complete axillary dissection, a procedure preserving specifically lymph nodes in relation to the arm. Methods Twenty-one patients with an operable breast cancer requiring an axillary dissection underwent surgery with an attempt to separate nodes related to the breast from specific nodes related to the arm. After an injection of blue dye in the arm, the surgeon performed the axillary dissection trying to identify blue nodes and ducts in order to preserve lymphatic arm drainage (LAD). If the blue nodes were located in the normal axillary dissection, they were removed separately. Results In 15 of 21 patients (71%), blue nodes in relation with LAD were identified. In 10 (47%) patients, it was possible to dissect the LAD with the preservation lymphatic ducts. In 10 patients, the LAD nodes were removed: none of them contained metastases, despite the fact that the non-LAD axillary nodes contained metastases in 7 of 10 cases. Conclusions Identifying the LAD with blue dye injection in the arm is possible. A subsequent study can now begin to determine if this procedure is safe for patients and able to prevent lymphedema of the arm.     

Sentinel lymph node mapping in breast cancer using subareolar injection of blue dye

Background: Lymphatic mapping in breast cancer performed solely by intraparenchymal injections of blue dye remains an accepted method of identifying sentinel nodes, largely because of its simplicity. As currently practiced, the technique is associated with a marked learning curve, variable identification rates of sentinel nodes, and high false-negative rates. The purpose of this study is to improve dye-only lymphatic mapping of the breast by using an alternative site for injection of blue dye: the subareolar lymphatic plexus.

Study Design: In the 10 months between August 1998 and May 1999, 40 women with operable breast cancer in stages I and II underwent lymphatic mapping and sentinel node biopsy performed solely by subareolar injections of blue dye, followed by complete axillary node dissection. The technique involved the injection of 5 mL of 1% isosulfan blue into the subareolar plexus, which consists of breast tissue located immediately beneath the areola. No peritumoral injections of blue dye were performed. The ability of subareolar dye injections to identify sentinel nodes and accurately predict the pathologic status of the axilla was determined and compared with published results for dye-only lymphatic mapping using intraparenchymal injections.

Results: The identification rate of sentinel nodes was 98% (in 39 of 40 patients). Axillary basins harboring positive lymph nodes were found in 15 of these 39 patients (38.5%). Sentinel nodes correctly predicted the status of these 15 positive axillary basins in 100% of the patients. There were no false-negative sentinel node biopsies, indicating a false-negative rate of 0 (in 0 of 15). The overall accuracy, sensitivity, and specificity were 100%.

Conclusions: Compared with other series of dye-directed lymphatic mapping, the present study of dye-only injections into the subareolar plexus demonstrates a high sentinel node identification rate, absent false-negative rate, and rapid learning curve. On the basis of these findings, we propose that injections into the subareolar lymphatic plexus are the optimal way to perform dye-only lymphatic mapping of the breast.     

Axillary dissection after unsuccessful sentinel lymphadenectomy for breast cancer.

Intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL) has been demonstrated to provide sensitive axillary staging for breast cancer. LM/SL has a steep learning curve, and factors associated with unsuccessful LM/SL are not well known. Two hundred sixty patients with breast carcinoma and clinically negative axillae underwent injection of about 5 cm3 of isosulfan blue dye (Lymphazurin, US Surgical Corp, Norwalk, CT) into breast tissue surrounding a cancer or biopsy site. After 5 minutes of breast compression, blue-stained lymph nodes were sought. In 47 patients, no blue nodes were detected; a standard axillary dissection was performed. All 47 patients were women with a mean age of 56 years (range, 34-80). Ductal carcinoma was most common (91.5%). Mean tumor size was 1.99 cm. Axillary dissection yielded a mean of 15.8 lymph nodes (range, 6-35). Sixteen patients (34%) had positive lymph nodes (mean, 7.6; median, 6; range, 1-24). Factors associated with LM/SL difficulty include surgeon inexperience, medial hemisphere primary location, extensive axillary metastases, and extranodal invasion. Inability to identify a sentinel node in a clinically negative axilla is a risk factor for extensive axillary tumor burden. Axillary dissection should be performed for patients with unsuccessful LM/SL, particularly those with lateral hemisphere primaries.     

Sentinel Lymph Node Biopsy for Melanoma: How Many Radioactive Nodes Should be Removed?

Background: Sentinel lymph node (SLN) biopsy has become a standard method of staging patients with cutaneous melanoma. Sentinel lymph node biopsy usually is performed by intradermal injection of a vital blue dye (isosulfan blue) plus radioactive colloid (technetium sulfur colloid) around the site of the tumor. Intraoperative gamma probe detection has been shown to improve the rate of SLN identification compared to the use of blue dye alone. However, multiple sentinel nodes often are detected using the gamma probe. It is not clear whether these additional lymph nodes represent true sentinel nodes, or second-echelon lymph nodes that have received radiocolloid particles that have passed through the true sentinel node. This analysis was performed to determine the frequency with which these less radioactive lymph nodes contain metastatic disease when the most radioactive, or hottest, node does not.Materials and Methods: In the Sunbelt Melanoma Trial, 1184 patients with cutaneous melanoma of Breslow thickness 1.0 mm or more had sentinel lymph nodes identified. Sentinel lymph node biopsy was performed by injection of technetium sulfur colloid plus isosulfan blue dye in 99% of cases. Intraoperative determination of the degree of radioactivity of sentinel nodes (ex vivo) was measured, as well as the degree of blue dye staining.Results:Sentinel nodes were identified in 1373 nodal basins in 1184 patients. A total of 288 of 1184 patients (24.3%) were found to have sentinel node metastases detected by histology or immunohistochemistry. Nodal metastases were detected in 306 nodal basins in these 288 patients. There were 175 nodal basins from 170 patients in which at least one positive sentinel node was found and more than one sentinel node was harvested. Blue dye staining was found in 86.3% of the histologically positive sentinel nodes and 66.4% of the negative sentinel nodes. In 40 of 306 positive nodal basins (13.1%), the most radioactive sentinel node was negative for tumor when another, less radioactive, sentinel node was positive for tumor. In 20 of 40 cases inding a positive sentinel node other than the hottest node.Conclusions: If only the most radioactive sentinel node in each basin had been removed, 13.1% of the nodal basins with positive sentinel nodes would have been missed. It is recommended that all blue lymph nodes and all nodes that measure 10% or higher of the ex vivo radioactive count of the hottest sentinel node should be harvested for optimal detection of nodal metastases.Preliminary findings presented at the annual meeting of the Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999.     

染料法前哨淋巴结活检治疗乳腺癌进展

本旨在复习前哨淋巴结活检术的发展过程和乳腺的淋巴引流解剖，总结染料法前哨淋巴结活检术在乳腺癌诊治中的临床意义。乳腺癌的淋巴转移常常首先到达腋窝前哨淋巴结，染料法前哨淋巴结活检术对腋窝淋巴结是否受累以及是否需行清扫有确切指导作用。当染料法前哨淋巴结活检阴性时，可不必常规行腋窝淋巴结清扫术，由此可避免后带来的并发症和痛苦。     

Methylene blue dye as an alternative to isosulfan blue dye for sentinel lymph node localization

Abstract: Isosulfan blue dye has been used with increasing frequency in localizing sentinel lymph nodes in breast cancer patients. Few alternative types of dye have been investigated. In a prospective study of 30 patients, methylene blue dye was used instead of isosulfan blue dye to localize the sentinel lymph node. The methylene blue dye localization technique was successful in 90% of patients. These results are similar to those for isosulfan blue dye. This study describes methylene blue dye localization as a successful alternative to isosulfan dye in identifying the sentinel node in breast cancer patients. The methylene blue dye technique offers a substantial cost reduction.     

Reliable lymphatic drainage to axillary sentinel lymph nodes regardless of tumor location within the breast.

BACKGROUND: This analysis was performed in order to determine whether primary tumor location in breast cancer affects the axillary sentinel lymph node (SLN) identification (ID) rate, the false negative (FN) rate, incidence of axillary nodal metastases, or the number of SLN identified. METHODS: In this prospective multi-institutional study, SLN biopsy was performed on clinical stage T1-2, N0 breast cancer patients using blue dye alone or in combination with radioactive colloid, followed by completion axillary LN dissection. RESULTS: Central tumor location was associated with an improved FN rate, which may be related to reliable drainage from the subareolar lymphatic plexus. Tumor location did not significantly affect the SLN ID rate or the mean number of SLN identified. Medial tumor location was associated with a decreased rate of axillary nodal metastasis. CONCLUSIONS: Breast cancers drain reliably to the axillary lymph nodes regardless of tumor location within the breast.     

Lymphatic mapping and sentinel node biopsy in gastric cancer

BACKGROUND: To determine the feasibility and significance of lymphatic mapping and sentinel lymph node biopsy (SLNB) in patients with gastric cancer. METHODS: From August 1999 to January 2002, 27 gastric cancer patients underwent lymphatic mapping and sentinel lymph node biopsy using isosulfan blue dye. RESULTS: The success rate of SLNB was 96.3% (26 of 27). Accuracy, sensitivity, and specificity were 100%. There were no false negatives. In 26 successful cases, 8 patients had positive sentinel lymph nodes and 18 had negative sentinel nodes. Of 8 patients with positive sentinel nodes, 6 had positive sentinel nodes only at N1 lymph node station, 1 only at N2 station, and 1 had positive sentinel nodes at both N1 and N2 stations. Of 18 patients with negative sentinel lymph nodes, 9 patients had sentinel nodes only at N1, 3 only at N2, 5 at both N1 and N2, and 1 at both N1 and N3. There were no cases in which sentinel lymph nodes were the only sites of metastases. CONCLUSIONS: Sentinel lymph node biopsy using isosulfan blue dye in gastric cancer is a feasible procedure with high sensitivity and accuracy. Sentinel lymph nodes demonstrate the varied lymphatic drainage. If the sentinel nodes at N2 are positive, it will guide surgeons to do a more extended lymph node dissection in early stage gastric cancer.     

The Role of Sentinel Lymph Node Biopsy with Blue Dye Alone in Breast Cancer Patients with Excisional Biopsy

Purpose : Sentinel lymph node biopsy (SLNB) appears to offer an excellent alternative method to routine axillary lymph node dissection for staging patients with breast cancer. The aim of this study is to evaluate the effect of excisional biopsy on identification and false negative rate of sentinel lymph node biopsy with blue dye alone in breast cancer patients with clinically negative axilla.

Material and Methods : From March 1998 to March 2003, 266 consecutive sentinel lymph node biopsies (SLNB) were performed using isosulfan blue dye alone. Patients were divided into two groups. One hundred and four patients (39.1%) had previously undergone an excisional biopsy (Group I); in 162 patients (60.9%), pre-operative diagnosis was obtained by either fine-needle aspiration biopsy (FNAB) or core biopsy (Group II). Following sentinel lymph node biopsy, all patients had axillary lymph node dissection (ALND). Data concerning patients, sentinel lymph nodes and the status of the axilla were collected and compared using Fisher’s exact test. A p value of less than 0.05 was considered statistically significant.

Results : The sentinel lymph node was successfully identified by blue dye in 94.3% (251/266) of patients. Mean lymph nodes removed from the axilla was 19 (range 11–36) and the mean number of sentinel nodes was 2 (range 1–5). The identification and false negative rate were unrelated to size, type or location of the tumour, or a previous surgical biopsy. Conclusions : SLNB with blue dye for evaluation of the axilla is a rapid and accurate technique that provides increased efficacy in the detection of lymphatic metastasis when careful pathologic evaluation with serial sections is performed. The risk-benefit analysis of lymphatic mapping with blue dye provides improvement in staging, with reduced morbidity and hospital stay, and the elimination of general anaesthesia. The technique may also be used safely and accurately in breast cancer patients with excisional biopsy.     

Sentinel lymphadenectomy accurately predicts nodal status in T2 breast cancer

Background: Sentinel lymph node biopsy (SLNB) has emerged as a reliable, accurate method of staging the axilla for early breast cancer. Although widely accepted for T1 lesions, its use in larger tumors remains controversial. This study was undertaken to define the role of SLNB for T2 breast cancer.

Study Design: From a prospective breast sentinel lymph node database of 1,627 patients accrued between September 1996 and November 1999, we identified 223 patients with clinical T1-2N0 breast cancer who underwent 224 lymphatic mapping procedures and SLNB followed by a standard axillary lymph node dissection (ALND). Preoperative lymphatic mapping was performed by injection of unfiltered technetium 99 sulfur colloid and isosulfan blue dye. Data about patient and tumor characteristics and the status of the sentinel lymph nodes and the axillary nodes were analyzed. Statistics were performed using Fisher’s exact test.

Results: Two hundred four of 224 sentinel lymph node mapping procedures (91%) were successful. Median tumor size was 2.0 cm (range 0.2 to 4.8 cm). One hundred forty-five of the 204 patients had T1 lesions and 59 patients had T2 lesions. There were 92 pathologically positive axillae, 5 (5%) of which were not evident either by SLNB or by intraoperative clinical examination. The false-negative rate and accuracy were not significantly different between the two groups, but axillary node metastases were observed more frequently with T2 than with T1 tumors (p = 0.005); other factors, including patient age, prior surgical biopsy, upper-outer quadrant tumor location, and tumor lymphovascular invasion were not associated with a higher incidence of false-negative SLNB in either T1 or T2 tumors.

Conclusions: SLNB is as accurate for T2 tumors as it is for T1 tumors. Because no tumor or patient characteristics predict a high false-negative rate, all patients with T1-2N0 breast cancer should be considered candidates for the procedure. Complete clinical examination of the axilla should be undertaken to avoid missing palpable axillary nodal metastases.     

Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group

INTRODUCTION: Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate. METHODS: Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection. RESULTS: SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01). CONCLUSIONS: These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.     

Sentinel node involvement in T0-T1 breast cancers]

STUDY AIM: Determination of axillary lymph node status is crucial in diagnosis of early breast cancer. However thanks to an early diagnosis, an increasing number of axillary lymph node dissections are free of disease. This raises questions about the need for this procedure. The study aim was to report an experience with lymphadenectomy and sentinel node mapping in patients with T0-T1 carcinoma of the breast. METHODS: Between November 1997 and December 1999, 84 consecutive women (T0-T1 N0 according to the 1987 UICC classification) with recently diagnosed breast cancer, were included in this study for identification of the sentinel lymph node (SLN). The SLN was removed and submitted for histological examination. All patients underwent axillary dissection; nodes from levels I and II (Berg's classification) were excised and submitted to histological examination. RESULTS: The average tumor diameter was 12.7 mm (range, 3 to 25 mm). The lymphatic mapping technique was obtained after injection of the isotope into the breast around the tumor in 53/84 patients: the sentinel lymph node was the only positive node in 10 patients and it was positive in 5 patients with other axillary nodes. In 15/84 patients, an intradermal injection of blue dye was used; two sentinel nodes were positive and one falsely negative. In 16/84 patients, an interdermal injection of blue dye was used to make up for. In this study, the sentinel node was positive in three patients and falsely negative in one patient. The discrepancy was due to an important involvement of an axillary area excluded from the lymphatic channels. 22/84 patients (26%) had a metastatic spread to the axillary nodes. 30/84 patients had also an isotopic captation in another lymph node group (internal mammary). CONCLUSION: This study confirms that lymphatic mapping is technically possible in the patients with T0-T1 breast cancer and that the histological characteristics of the sentinel node probably reflect the histological characteristics of the rest of the axillary lymph nodes, but do not provide any information about the other lymph node sites.     

Carbon dye as an adjunct to isosulfan blue dye for sentinel lymph node dissection.

BACKGROUND: The success of intraoperative lymphatic mapping depends on accurate identification of the sentinel node. We hypothesized that a carbon particle suspension would allow histopathologic confirmation of the sentinel lymph node through deposition of carbon within that node. METHODS: An animal model was used to compare the lymphatic mapping accuracy of carbon dye with that of isosulfan blue dye, the standard agent for intraoperative visualization of the sentinel lymph node. Twenty-two rats underwent lymphatic mapping in each distal lower extremity with various combinations of carbon dye and isosulfan blue dye. All stained (blue or black) nodes in the inguinal drainage basin were removed for pathologic analysis, including carbon particle analysis. A meticulous search identified all nonstained (nonsentinel) nodes in the same basin. These nonsentinel nodes were examined for carbon particles by light microscopy. Dermal diffusion of mapping agents at the injection site was also recorded. Animals were then observed for 28 days to assess the toxicity of mapping agents. RESULTS: Although isosulfan blue dye and full-strength carbon dye each stained all sentinel nodes, the latter obscured histologic detail. The combination of 2.5% carbon dye, 7.5% saline solution, and 90% isosulfan blue dye also stained all sentinel nodes; carbon particles were seen on light microscopy in all 13 stained nodes and did not interfere with histologic evaluation. No unstained node contained carbon particles, although the number of nonsentinel nodes was small. Carbon dye exhibited significantly less intradermal diffusion than isosulfan blue dye, but the carbon left a permanent mark on the skin. No toxicity or side effect associated with the use of carbon dye was observed. CONCLUSION: Carbon dye allows histopathologic confirmation of sentinel lymph nodes identified by isosulfan blue dye.     

Sentinel lymph node drainage in multicentric breast cancers

Axillary lymph node status is the most important prognostic marker in patients with breast cancer; the presence of axillary metastases impacts prognosis as well as subsequent systemic therapy. Axillary lymph node dissection (ALND) is associated with significant morbidity and psychological distress; the introduction of sentinel lymph node (SLN) biopsy with lymphatic mapping affords the ability to identify those patients most likely to benefit from ALND, sparing node-negative patients. The lymphatic drainage of the breast is poorly understood, and the situation is further complicated by the lack of standardization of the SLN biopsy technique among institutions. Multicentricity has generally been considered to be a contraindication to SLN biopsy due to concerns about potential inaccuracies. Here we report five cases of patients with multicentric breast cancers (two tumors in two distinct quadrants). In each case, injection of one site with technetium-labeled sulfur colloid and the second site with isosulfan blue dye resulted in successful identification of at least one node that was both hot and blue within the axilla. These observations suggest that the lymphatic drainage of the entire breast coincides with drainage of the tumor bed, regardless of the quadrant. However, further studies are needed to validate the accuracy of SLN biopsy in multicentric breast cancers.     

术中淋巴显影和前哨淋巴结概念在乳腺癌手术中的研究

目的 探讨术中淋巴显影和前哨淋巴结活检在乳腺癌手术中应用的可行性。方法 选取患有乳腺癌的150个病人，手术前取5ml专利蓝（patent blue）在皮肤消毒前注射入肿瘤周围的乳腺实质内，术后解剖标本组织寻找蓝染的淋巴管，循淋巴管解剖蓝染的淋巴结即前哨淋巴结和未被染色的淋巴结，蓝染的淋巴结和无染色的淋巴结常规HE染色病理学检查。阴性的蓝染淋巴结行常规的免疫组化。结果 144例病人淋巴显影并找到蓝染的前哨淋巴结。淋巴显影率为96％。所有淋巴结行病理学HE染色。淋巴显影的144位病人确诊80例有淋巴结转移，有淋巴结转移的80例病人中有76例的前哨淋巴结确诊有转移，只有4个病人的前哨淋巴结为阴性，假阴性率为5％。结论 在乳腺癌手术中使用专利蓝染料显示淋巴是可行的。前哨淋巴结能预测剩余淋巴结的实际状态。淋巴显影和前哨淋巴结的概念对乳腺癌手术有指导的意义。